From 6fa4f56bc4f2a063ee7eb05c187059ff27aae8db Mon Sep 17 00:00:00 2001
From: Matijs van Zuijlen <matijs@matijs.net>
Date: Sun, 3 Oct 2021 18:06:36 +0200
Subject: [PATCH] - lexer.rl: Fix handling of beginless ranges at start of line

This fixes an issue where beginless ranges at the start of a line would
be interpreted as continuing an expression starting on the previous
line. Unlike leading dots for method calls, `..` and `...` at the start
of a line do not continue an expression from the previous line.
---
 lib/parser/lexer.rl | 22 ++++++++++++++++++++++
 test/test_lexer.rb  | 26 ++++++++++++++++++++++++++
 test/test_parser.rb | 23 +++++++++++++++++++++++
 3 files changed, 71 insertions(+)

diff --git a/lib/parser/lexer.rl b/lib/parser/lexer.rl
index 718c1d8bf..ef3772dbd 100644
--- a/lib/parser/lexer.rl
+++ b/lib/parser/lexer.rl
@@ -2513,6 +2513,28 @@ class Parser::Lexer
         end
       };
 
+      c_space* '..'
+      => {
+        emit(:tNL, nil, @newline_s, @newline_s + 1)
+        if @version < 27
+          fhold; fnext line_begin; fbreak;
+        else
+          emit(:tBDOT2)
+          fnext expr_beg; fbreak;
+        end
+      };
+
+      c_space* '...'
+      => {
+        emit(:tNL, nil, @newline_s, @newline_s + 1)
+        if @version < 27
+          fhold; fnext line_begin; fbreak;
+        else
+          emit(:tBDOT3)
+          fnext expr_beg; fbreak;
+        end
+      };
+
       c_space* %{ tm = p } ('.' | '&.')
       => { p = tm - 1; fgoto expr_end; };
 
diff --git a/test/test_lexer.rb b/test/test_lexer.rb
index 192247718..e0c296dfd 100644
--- a/test/test_lexer.rb
+++ b/test/test_lexer.rb
@@ -602,10 +602,36 @@ def test_dot
 
   def test_dot2
     assert_scanned "..", :tDOT2, "..", [0, 2]
+    refute_scanned("foo\n..42",
+                   :tIDENTIFIER, "foo", [0, 3],
+                   :tNL,         nil,   [3, 4])
+  end
+
+  def test_dot2_27
+    setup_lexer 27
+    assert_scanned "..", :tBDOT2, "..", [0, 2]
+    assert_scanned("foo\n..42",
+                   :tIDENTIFIER, "foo", [0, 3],
+                   :tNL,         nil,   [3, 4],
+                   :tBDOT2,      "..",  [4, 6],
+                   :tINTEGER,    42,    [6, 8])
   end
 
   def test_dot3
     assert_scanned "...", :tDOT3, "...", [0, 3]
+    refute_scanned("foo\n...42",
+                   :tIDENTIFIER, "foo", [0, 3],
+                   :tNL,         nil,   [3, 4])
+  end
+
+  def test_dot3_27
+    setup_lexer 27
+    assert_scanned "...", :tBDOT3, "...", [0, 3]
+    assert_scanned("foo\n...42",
+                   :tIDENTIFIER, "foo", [0, 3],
+                   :tNL,         nil,   [3, 4],
+                   :tBDOT3,      "...", [4, 7],
+                   :tINTEGER,    42,    [7, 9])
   end
 
   def test_equals
diff --git a/test/test_parser.rb b/test/test_parser.rb
index 2b0cdb509..d195e682f 100644
--- a/test/test_parser.rb
+++ b/test/test_parser.rb
@@ -911,6 +911,29 @@ def test_beginless_range
     )
   end
 
+  def test_beginless_irange_after_newline
+    assert_parses(
+      s(:begin,
+        s(:lvar, :foo),
+        s(:irange, nil,
+          s(:int, 100))),
+      %Q{foo\n..100},
+      %q{},
+      SINCE_2_7
+    )
+  end
+
+  def test_beginless_erange_after_newline
+    assert_parses(
+      s(:begin,
+        s(:lvar, :foo),
+        s(:erange, nil,
+          s(:int, 100))),
+      %Q{foo\n...100},
+      %q{},
+      SINCE_2_7
+    )
+  end
   #
   # Access
   #